1. Technical Field
Embodiments of the present invention relate to an apparatus for producing a detachable information sheet that includes an electrophotographic image forming apparatus, and a method for producing a detachable information sheet.
2. Related Art
Catalogs, covers, DM postcards, etc. conventionally with images and texts formed by printing have been used for predetermined purposes.
For these use applications, the printing surfaces may be protected with surface treatment or film in some cases in order to protect from water leakage and contamination or provide gloss.
Examples of the surface treatment include overprint, vinyl coating, and press coat, which need to be applied after printing. Recently, treatment with ultraviolet curable compositions has become mainstream in terms of cost and environmental consciousness.
In addition, for DM postcards, etc., an approach is used in such a way that print sides with information input are subjected to pressure bonding to conceal the information, which are detachable when needed. While latex rubbers, ultraviolet curable pressure-sensitive compositions, and the like are used for the adhesive, the ultraviolet curable pressure-sensitive compositions have become mainstream as in the case of surface treatment.
In addition, recently, information has been frequently modified, and accordingly there are increasing number of systems that are able to output variable information such as information modified for each copy, acceleration of printout has been desired, and on-demand printing has been used as a printing method which is suitable for the acceleration.
Machines for use in on-demand printing typically include electrophotographic machines and ink-jet machines, and the electrophotographic methods using toners have become mainstream for output including images.
The colors of images recorded by the electrophotographic methods are reproduced by fixing powdery color materials referred to as toners onto recording media with heat, pressure, etc.
In addition, as for the ultraviolet curable compositions, some commercially available ultraviolet curable compositions are commonly used for offset printing. However, the use of the commercially available ultraviolet curable compositions for images recorded by the electrophotographic methods may result in a failure to obtain satisfactory results, because of incompatibility between toners and the ultraviolet curable compositions. In general, toners are composed of resins, colorants such as pigments, additives such as silica, waxes, etc., and some of fixed toners have colorants, additives, etc. present as powders or incompletely dissolved, and thus have a certain number of gaps generated. It is often the case that the ultraviolet curable compositions permeate the gaps, which exhibits incompatibility therebetween.
The varnish composition and preparation method therefor disclosed in JP-2007-277547-A improve the compatibility by fixing oil applied on the prints, through a water-based film-forming agent containing no ammonia and having a low static surface tension. In addition, the resin forming apparatus and an apparatus including the resin forming apparatus, which are disclosed in JP-3570853-B (JP-H10-309876-A), form a silicon resin layer on print sides to provide protection for the print surfaces, waterproof treatment, gloss, etc. In addition, for a metal container with a printed surface and a method for printing on the metal container as disclosed in JP-2522333-B (JP-H01-163747-A), a wide variety of prints in small quantities can be efficiently achieved through the use of an electrophotographic method, and toner layers can be protected and provided with gloss by processing with an ultraviolet curable composition.
In addition, JP-3827124-B (JP-H11-349854-A) discloses a detachable ultraviolet curable pressure-sensitive composition for use in DM postcards, etc. In addition, JP-4471334-B (JP-2004-231890-A) discloses an ultraviolet curable pressure-sensitive adhesive composition matched with liquid toners.
In particular, for the ultraviolet curable composition disclosed in JP-3827124-B (JP-H11-349854-A), the presence of a (meth)acrylic copolymer (B) is critically important, which has an average molecular weight of 10000 to 100000, and a glass transition temperature of −35.2° C. to 20° C.
The (meth)acrylic copolymer (B) is a straight-chain polymer, which has pressure-sensitive adhesiveness. On the other hand, an ultraviolet curing component (a) basically has no pressure-sensitive adhesiveness, even when the component (a) is cured with ultraviolet light. The ultraviolet curing substance in the ultraviolet curing component (a) is hard, and present to surround the (meth)acrylic copolymer (B), which serves to prevent tackiness at the surface of the (meth)acrylic copolymer (B) before pressure bonding and after detachment, and keep the copolymer (B) from being pressure-bonded again at pressures applied by people in normal life.
When extremely strong pressure is applied to the substance (pressure bonding is carried out), the (meth)acrylic copolymer (B) is attached to the copolymer (B) to develop adhesiveness. However, the bond between the (meth)acrylic copolymers (B) moves the ultraviolet curing substance in the ultraviolet curing component (a), and the copolymers (B) are thus bonded with stress left by the resilience of the ultraviolet curing substance in the ultraviolet curing component (a). Therefore, peeling with a strong force can achieve clear detachment.
However, even with these techniques, the combination of dry toner with the ultraviolet curable composition may result in peeling of toner images in some cases due to poor matching between the toner images and the ultraviolet curable composition, even when the ultraviolet curable composition can be applied. More specifically, when toner images are subjected to pressure bonding with the ultraviolet curable composition disclosed in JP-3827124-B (JP-H11-349854-A), a lack of peeling strength may result in a failure to withstand vibrations at the time of transportation, or conversely, excessively high peeling strength may result in peeling of one image when detachment is carried out. In addition, even if there is no problem immediately after the pressure bonding, the bonding strength may lack or be conversely increased during storage, and for toner images, the composition is not developed to a practical level at all.
In addition, ultraviolet curable pressure-sensitive compositions for use as detachable adhesive agents for use in DM postcards, etc. also have poor matching with dry toner images, and the toner images may be peeled at the time of detachment.
As just described, in the related art described above, the combination of toner with the ultraviolet curable composition or the ultraviolet curable pressure-sensitive composition results in poor matching, thereby failing to achieve protection, provide gloss, or achieve detachable pressure bonding by applying and curing the ultraviolet curable composition or the ultraviolet curable pressure-sensitive composition on toner images.
Conventionally, for electrophotographic images, silicon oil is used as a fixation peeling agent, and the use of images formed with the use of silicon oil somewhat reduces peeling of the images in detachment (for example, see JP-2009-169337-A). However, the reduction has not been developed to a level for use as direct mail.
In addition, recently, in order to prevent offices from being contaminated by silicon oil and prevent image quality from being degraded due to a shortage of silicon oil, so-called oilless toners containing therein wax have been commonly used. Furthermore, on the request of energy conservation, so-called low-temperature fixing toners have been used in which resins are used for low toner softening temperatures.
However, when energy-ray curable precursors are to be provided on toner images subjected to such oilless fixing, there is a problem that the following defects are caused.
Defect (1) the wax on the toner image surface repels the energy-ray curable precursor to reduce the thickness of the energy-ray curable precursor layer in a large image area, and the precursor directly serves as an energy-ray curable pressure-sensitive adhesive, thus partially failing to be pressure-bonded, and resulting in peeling of the information sheet depending on vibrations and handling at the time of transportation.
Defect (2) with the poor bondability between the cured energy-ray curable pressure-sensitive adhesive and the toner image subjected to oilless fixing, the detachment causes the energy-ray curable pressure-sensitive adhesive to be partially peeled from one side, resulting in an unsightly image with image quality significantly decreased.